BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	6 Months Ended
	Apr. 30, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The interim condensed consolidated financial statements have been prepared in accordance with the U.S. Securities and Exchange Commission (“SEC”) instructions to Quarterly Reports on Form 10-Q and include all of the information and disclosures required by accounting principles generally accepted in the United States (“GAAP”) for interim financial reporting. The preparation of financial statements in conformity with GAAP requires management to make certain estimates and assumptions that affect the amounts reported in the interim condensed consolidated financial statements and accompanying notes. Actual amounts could differ from those estimates. The 2024 fiscal year of Greif, Inc. and its subsidiaries (the “Company”) began on November 1, 2023 and ended on October 31, 2024. Any references to the 2024 fiscal year or to any quarter of that year, relates to the fiscal year or quarter, as the case may be, ended October 31, 2024, unless otherwise stated. The Company is changing its fiscal year, effective for the 2025 fiscal year. The 2025 fiscal year began on November 1, 2024 and will end on September 30, 2025, and accordingly, will consist of eleven months. The Company’s fourth fiscal quarter of 2025 will be the two-month period ending September 30, 2025. Thereafter, the Company’s fiscal year will begin on October 1 and end on September 30 of the following year. The information filed herein reflects all adjustments that are, in the opinion of management, necessary for a fair presentation of the interim condensed consolidated balance sheet as of April 30, 2025 and the condensed consolidated balance sheet as of October 31, 2024, the interim condensed consolidated statements of income, comprehensive income and changes in shareholders’ equity for the three and six months ended April 30, 2025 and 2024 and the interim condensed consolidated statements of cash flows for the six months ended April 30, 2025 and 2024 of the Company. The interim condensed consolidated financial statements include the accounts of Greif, Inc., all wholly-owned and consolidated subsidiaries and investments in limited liability companies, partnerships and joint ventures in which it has controlling influence or is the primary beneficiary. Non-majority owned entities include investments in limited liability companies, partnerships and joint ventures in which the Company does not have controlling interest and are accounted for using either the equity or cost method, as appropriate. The unaudited interim condensed consolidated financial statements included in this Quarterly Report on Form 10-Q (this “Form 10-Q”) should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for its fiscal year ended October 31, 2024 (the “2024 Form 10-K”).
Recast of Certain Prior Period Information	Recast of Certain Prior Period Information In December 2024, the Company announced changes to its reporting structure, moving to a material solution-based structure. The Company believes this structure will enable the Company to more efficiently utilize its robust scale and global network of facilities, align operations to capitalize on its deep subject matter expertise, enable further innovation and growth, and optimize cross-selling and margin expansion opportunities. This internal re-alignment has resulted in a change in the Company’s reportable segments. Prior period segment information for the 2024 fiscal year has been recast to conform to the way the Company internally manages and monitors its business during the 2025 fiscal year. The recast of prior period information had no impact on the Company’s interim condensed consolidated balance sheets, interim condensed consolidated statements of income, interim condensed consolidated statements of comprehensive income, interim condensed consolidated statements of changes in shareholders’ equity and the interim condensed consolidated statements of cash flows.
Newly Adopted and Recently Issued Accounting Standards	Newly Adopted Accounting Standards There have been no new accounting standards adopted since the filing of the 2024 Form 10-K that have significance, or potential significance, to the interim condensed consolidated financial statements. Recently Issued Accounting Standards In December 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-09, “Income Taxes (Topic 740): Improvements to Tax Disclosures,” which is intended to improve the effectiveness of income tax disclosures. This ASU is effective for fiscal years beginning after December 15, 2024, with early adoption permitted. The effective date for the Company to adopt this ASU is for the fiscal year beginning October 1, 2025. The Company is in the process of determining the potential impact of adopting this guidance on its financial position, results of operations, comprehensive income, cash flow and disclosures. In November 2023, the FASB issued ASU 2023-07, “Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures,” which is intended to improve reportable segment disclosure requirements. This ASU is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. The effective date for the Company to adopt this ASU is for the fiscal year and interim periods beginning November 1, 2024 and October 1, 2025 respectively. The Company is in the process of determining the potential impact of adopting this guidance on its financial position, results of operations, comprehensive income, cash flow and disclosures. In November 2024, the FASB issued ASU 2024-03, “Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses,” which is intended to improve disclosures related to the Company’s certain income statement expenses. This ASU is effective for fiscal years beginning after December 15, 2026, and interim periods within fiscal years beginning after December 15, 2027, with early adoption permitted. The effective date for the Company to adopt this ASU is for the fiscal year and interim periods beginning October 1, 2027 and October 1, 2028 respectively. The Company is in the process of determining the potential impact of adopting this guidance on its financial position, results of operations, comprehensive income, cash flow and disclosures.